Substantially flat or planar articles, having substantial thickness and length dimensions, such as, for example, plate glass members, garage doors, and the like, need to be protected during, for example, transportation and shipping thereof from their manufacturing facilities to their storage and/or point of sale locations so as to prevent damage from occurring to such articles prior to the purchase of the same by consumers. It is conventional practice to utilize substantially rigid, laminated U-shaped channel structures so as to effectively define composite packaging containers, which encase the articles therewithin, whereby the channel structures can subsequently be secured together by means of, for example, suitable strapping or banding. One type of conventional packaging structure, which has been utilized for the foregoing purposes, is disclosed, for example, within U.S. Pat. No. 4,976,374 which issued to Macaluso on Dec. 11, 1990. More particularly, as disclosed within FIG. 1, which substantially corresponds to FIG. 3 of the aforenoted patent, it is seen that the composite packaging container comprises a substantially U-shaped base unit 10 and a substantially U-shaped cover unit 12. The substantially U-shaped base unit 10 is seen to comprise a base or bottom portion 10a, and a pair of oppositely disposed, upstanding side wall portions or leg members 10b, 10c integrally connected to the base or bottom portion 10a, while the substantially U-shaped cover unit 12 is seen to comprise a cover or top portion 12a, and a pair of oppositely disposed, dependent side wall portions or leg members 12b, 12c integrally connected to the cover or top portion 12a. 
When the articles 18 are to be disposed within the composite packaging container, the articles 18 are initially inserted within the substantially U-shaped base unit 10 so as to be interposed between the oppositely disposed, upstanding side wall portions or leg members 10b, 10c thereof, and simultaneously supported upon the base or bottom portion 10a of the base unit 10, and subsequently, the substantially U-shaped cover unit 12 is disposed over the substantially U-shaped base unit 10 so as to be structurally mated therewith in order to effectively form the composite packaging container in which the articles 18 are adapted to be encased. Lastly, the base unit 10 and the cover unit 12 are secured together by means of suitable strapping or banding 16. It is noted, however, that the base units 10 and the cover units 12 comprise substantially rigid and inflexible structures, and accordingly, it can therefore be appreciated that the oppositely disposed, upstanding side wall portions or leg members 10b, 10c of the base unit 10 are separated from each other by means of, for example, a predeterminedly fixed distance defined therebetween. Therefore, it is sometimes difficult to properly insert the articles 18, having a predetermined lateral extent or width dimension which is only slightly less than the predetermined distance defined between the pair of oppositely disposed, upstanding side wall portions or leg members 10b, 10c. 
In addition to the aforenoted packaging structure as disclosed within the patent to Macaluso, a somewhat differently structured packaging structure is disclosed within U.S. Pat. No. 5,947,290 which issued to Loeschen on Sep. 7, 1999. As disclosed within FIG. 1a, which substantially corresponds to FIG. 1 of Loeschen, it is seen that the packaging structure, generally indicated by means of the reference character 10, comprises an upper base member 14 and a pair of dependent side members 16, 16. The dependent side members 16, 16 cooperate with the upper base member 14 so as to define therewith corner junctions 18, 18, and it is seen that such corner junctions 18, 18 are externally scored as at 20, 20 such that internal living hinges are defined as at 22. Such hinge structures, however, permit the dependent side members 16, 16 to therefore be moved laterally outwardly, in opposite directions, with respect to the upper base member 14 so as to be disposed, for example, at an angle of 50°, with respect to the upper base member 14. It can therefore be seen that this packaging structure 10 would not permit articles to be inserted into the containment space of the packaging structure in a laterally sideways direction, and does not provide a rigidly upstanding side wall against which side edge portions of the articles can be abutted and aligned.
A need therefore exists in the art for a new and improved packaging structure, an apparatus for making the same, and a composite packaging assembly, wherein the packaging structure can be structured so as to still have the substantially U-shaped cross-sectional configuration within which the articles can be accommodated and contained, and yet which is also uniquely structured so as to facilitate the insertion or disposition of substantially flat or planar articles into and within the packaging structure in a desirably aligned manner, and still yet further, to effectively automatically align side edge portions of the articles to be inserted and contained within the packaging structure.